Do a CHECK_FOR_INTERRUPTS after emitting a message of less than ERROR

severity.  This is to ensure the user can cancel a query that's spitting
out lots of notice/warning messages, even if they're coming from a loop
that doesn't otherwise contain a CHECK_FOR_INTERRUPTS.  Per gripe from
Stephen Frost.

src/backend/utils/error/elog.c

@@ -42,7 +42,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.174 2006/09/27 18:40:09 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.175 2006/10/01 22:08:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -451,7 +451,14 @@ errfinish(int dummy,...)
 		abort();
 	}
 
-	/* We reach here if elevel <= WARNING. OK to return to caller. */
+	/*
+	 * We reach here if elevel <= WARNING. OK to return to caller.
+	 *
+	 * But check for cancel/die interrupt first --- this is so that the user
+	 * can stop a query emitting tons of notice or warning messages, even if
+	 * it's in a loop that otherwise fails to check for interrupts.
+	 */
+	CHECK_FOR_INTERRUPTS();
 }